The Opisthobranch Molluscs from Porto Santo Island (Madeira Archipelago, Northeastern Atlantic) 1

Moluscos Opistobranquios de la Isla de Porto Santo (Archipiélago de Madeira, Atlántico Nordeste) 1

Manuel António E. MALAQUIAS*, Juan Lucas CERVERA**, António D. ABREU*** and Pablo J. LÓPEZ-GONZÁLEZ ****

Recibido el 24-XI-2000. Aceptado el 27-III-2001

ABSTRACT New data on the opisthobranch fauna from Porto Santo island (Madeira Archipelago) are presented. A list of the previously recorded sixteen species and their relatives references, together the first record of twelve additional species, is supplied.

RESUMEN En este trabajo se presentan nuevos datos sobre la fauna de moluscos opistobranquios de la isla de Porto Santo (Archipiélago de Madeira). Se confecciona una lista de las dieciseis especies previamente citadas en esta isla, junto a sus correspondientes referencias, la cual se ve incrementada con otras doce especies adicionales citadas por primera vez en esta contribución.

KEY WORDS : Mollusca, Opisthobranchia, Porto Santo, Madeira, Portugal. PALABRAS CLAVE : Mollusca, Opisthobranchia, Porto Santo, Madeira, Portugal.

INTRODUCTION

Among the islands of Madeira SIECK , 1972; N ORDSIECK AND GARCÍA - Archipelago, Porto Santo is one of the TALAVERA , 1979; W IRTZ , 1994; F ONSECA , less known with respect to the opistho - GUERREIRO AND GIL , 1995; W IRTZ , 1999). branchs. Only seven papers are known Porto Santo is the second largest to us referring the presence of 16 species island of Madeira archipelago and is of opisthobranchs in Porto Santo situated 21 miles on the Northeast of (WATSON , 1897; N OBRE , 1937; N ORD - Madeira island. It lies between 33° 07’ N

1 Contribution of the Instituto Português de Malacologia * Centro de Ciências do Mar, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, Campus de Gambelas, 8000 – 810 Faro, Portugal, [email protected] ** Departamento de Biologia Animal, Vegetal y Ecologia, Facultad de Ciencias del Mar, Universidad de Cádiz, Apartado 40 – 11510 Puerto Real, Cádiz, España, [email protected] *** Estação de Biologia Marinha do Funchal, Cais do Carvão, Promenade da Orla Marítima do Funchal, Gorgulho, 9000 - 107 Funchal, Portugal, [email protected] **** Laboratorio de Biología Marina, Departamento de Fisiología y Biología Animal, Facultad de Biología, Universidad de Sevilla, Av. Reina Mercedes 7, Apdo. 1095, 41080 Sevilla, España, [email protected]

75 Iberus , 19 (1), 2001

B A

Figure 1. (A) Madeira archipelago and (B) Porto Santo Island with sampling localities. 1 Ilhéu de Ferro; 2: Porto de Abrigo; 3: Pedras Altas; 4: Ilhéu do Farol; 5: Ponta da Galé; 6: Porto dos Frades; 7: Pontinha. Figura 1. (A) Archipiélago de Madeira y (B) Localidades de muestreo en la Isla de Porto Santo: 1: Ilhéu de Ferro; 2: Porto de Abrigo; 3: Pedras Altas; 4: Ilhéu do Farol; 5: Ponta da Galé; 6: Porto dos Frades; 7: Pontinha.

– 33° 00’ N and 16° 25’ W – 16° 17’ W and collected in eight different localities in a has an approximate area of 41 Km 2 with a total of ten sampling efforts, covering both coastal line of 38 Km. It is surrounded by the intertidal and the subtidal areas down seven islets, three of them with conside - to 20 meters depth. On the subtidal areas rable dimensions. The littoral of Porto the specimens were collected by SCUBA Santo is quite different from that of diving, using a suction device and by Madeira, mostly due to the presence of manual collecting after direct observation. calcareous rocks and a large sandy beach. Substratum covered with seaweeds, Whether these features are responsible or sponges, bryozoans and hydrozoans colo - not for any particular faunistical compo - nies were particularly searched. sition of Porto Santo’s littoral ecosystems After sieving, the specimens were is not yet known, by lacking of available studied with stereomicroscopes, photo - ecological information. graphed, fixed in formalin 4% and pre - As part of the research Programme served in ethanol 70%. OpisthoMadeira, launched in 1994 by The specimens were kept in the the Museu Municipal do Funchal (His - collections of the Museu Municipal do tória Natural), several field sampling Funchal (História Natural) (designated were carried on Porto Santo island, as MMF). which results are reported here together with a compilation of the previous bibliographical records. RESULTS

Fourteen species were collected and MATERIAL AND METHODS identified during the present Campaign (1 Cephalaspidea, 1 Anaspidea, 1 Saco - During the period of 18 to 23 Septem - glossa, 2 Tylodinoidea, 1 Pleurobran - ber 2000, opisthobranch molluscs were choidea, and 8 Nudibranchia) and

76 MALAQUIAS ET AL.: Opisthobranch molluscs from Porto Santo Island

Table I. Opisthobranch molluscs from Porto Santo island. Tabla I. Moluscos Opistobranquios de la Isla de Porto Santo.

Cephalaspidea Fischer, 1863 (sensu MIKKELSEN, 1996) Chelidonura africana Pruvot-Fol, 1953 Present account. Porto de Abrigo, 18th September 2000, one specimen with 3 mm in length. 22nd September 2000, one specimen (MMF31629) with 3mm in length, collected at night time under a floating jetty.

Cylichna cylindracea (Pennant, 1767) NORDSIECK (1972: 15), NORDSIECK AND GARCÍA-TALAVERA (1979: 170)

Pyrunculus spretus (Watson, 1897) WATSON (1897: 234), NOBRE (1937: 15)

Philine monterosatoi (Vayssière, 1885) NORDSIECK (1972: 22 as Philingwynia monterosati), NORDSIECK AND GARCÍA-TALAVERA (1979: 171)

Philine desmotis Watson, 1897 WATSON (1897: 236), NOBRE (1937: 17) and NORDSIECK AND GARCÍA-TALAVERA (1979: 172)

Retusa truncatula (Bruguière, 1792) WATSON (1997: 326 as Utriculus truncatulus), NORDSIECK (1972: 34 as Retusa mariei), NOBRE (1937: 14 as Tornatina truncatula)

Retusa mamillata (Brusina, 1865) NORDSIECK AND GARCÍA-TALAVERA (1979: 177 as Retusa (Mamilloretusa) mamillata)

Retusa leptoleinema (Brusina, 1865) NORDSIECK AND GARCÍA-TALAVERA (1979: 176 as Retusa leptoleynema)

Retusa tornata (Watson, 1883) NORDSIECK (1972: 36 as Semiretusa tornata), NORDSIECK AND GARCÍA-TALAVERA (1979: 177 as Semiretusa tornata)

Scaphander (W.) diaphana Aradas and Maggiore, 1839 WATSON (1897: 315), NOBRE (1937: 14)

Anaspidea Fischer, 1883 Aplysia parvula Guilding in Mörch, 1863 Present account. Porto de Abrigo, 20th September 2000, one specimen (MMF31626) with 20 mm in length. 22nd September, three specimens (MMF31631) with 2,5, 3 and 4 mm in length, collected during night time under a floating jetty.

Sacoglossa Ihering, 1876 Ascobulla fragilis (Jeffreys, 1856) WATSON (1897: 284) and NOBRE (1937: 16) Elysia flava Verril, 1901 Present account. Pontinha, 22nd September 2000, one specimen (MMF31636) with 9 mm in length, collected under a stone at 10 m depth.

Pleurobranchoidea Ferussac, 1822 Berthellina edwardsi (Vayssière, 1896) Present account. Ilhéu de Ferro (Southeast shore), 19th September, one specimen (MMF31637) with 13 mm in length, collected under a stone at 10 m depth.

Tylodinoidea Gray, 1847 Tylodina perversa (Gmelin in L., 1791) WIRTZ (1999: 6), Present account. Ilhéu de Ferro (Southeast shore), 19th September 2000, one specimen with 4 mm of shell length, collected near the sponge Aplysina aerophoba at 10 m depth. Pedras Altas, 20th September 2000, two specimens with 5 mm of shell length, collected near the sponge Aplysina aerophoba at 3 m depth. Ilhéu do Farol (Southeast shore), 21st September 2000, one specimen with 7 mm in length. Umbraculum umbraculum (Lightfoot, 1796) Present account. Pontinha, 22nd September 2000, one specimen (MMF31634) with 50 mm of shell length, collected crawling on a wall at 10 m depth.

77 Iberus, 19 (1), 2001

Table I. Continuation. Tabla I. Continuación.

Nudibranchia Blainville, 1814 Aegires sublaevis Odhner, 1931 Present account. Porto dos Frades, 21st September 2000, one specimen (MMF31624) with 3,5 mm in length, collected bellow algae between 0 and 1 m depth. Aldisa smaragdina Ortea, Pérez and Llera, 1982 Present account. Ilhéu de Ferro (Southeast shore), 19th September 2000, five specimens (MMF31641) with 10, 12, 14, 16 and 20 mm in length, under stones covered by a red sponge at approximately 10 m depth. Pedras Altas, 20th September 2000, one specimen with 23 mm in length, collected at 3 m depth, under a stone with red sponges. Chromodoris purpurea (Laurillard, 1831) Present account. Porto de Abrigo, 20th September 2000, one specimen (MMF31632) with 7 mm in length, collected under a stone at 4 m depth. Porto de Abrigo (out part of the west harbour protection near the beach), 23rd September 2000, one specimen (MMF3164) with 10 mm in length, collected under a stone between 4 to 5 m depth.

Discodoris atromaculata (Bergh, 1884) WIRTZ (1994: 169; 1999: 7)

Discodoris confusa Ballesteros, Llera and Ortea, 1984 WIRTZ (1999: 8), Present account. Ponta da Galé, 18th September 2000, one specimen with 40 mm in length, collected under a stone at 6 meters depth.

Hypselodoris bilineata (Pruvot-Fol, 1953) WIRTZ (1999: 7) Hypselodoris picta (d’Orbigny, 1839) Present account. Ilhéu de Ferro (Southeast shore), 19th September 2000, one specimen (MMF31623) with 50 mm in length, collected under a stone at 9 m depth Tambja ceutae García-Gómez and Ortea, 1988 Present account. Porto de Abrigo, 22nd September 2000, five specimens (MMF31627) with 4, 16, 20, 26 and 27 mm in length, collected at night time under a floating jetty on colonies of the bryozoan Bugula dentata.

Taringa cf. fanabensis Ortea and Martínez, 1992 WIRTZ (1999: 9) Platydoris argo (Linné, 1767) Present account. Ilhéu de Ferro (Southeast shore), 19th September 2000, two specimens (MMF31625) with 18 and 28 mm length, collected under stones at about 10 m depth. Pontinha, 22nd September 2000, two specimens (MMF31642) with 10 and 12 mm in length, collected under stones at about 10 m depth. Plocamopherus maderae (Lowe, 1842) Present account. Pontinha, 22nd September 2000, one specimen (MMF31622) with 20 mm in length, collected under a stone at 10 m depth.

(Right page) Figure 2. A: Chelidonura africana (10 mm; specimen collected at Porto Santo, 24th June 1999); B: Aplysia parvula (20 mm); C: Tylodina perversa (7 mm); D: Umbraculum umbraculum (50 mm of shell length); E: Elysia flava (9 mm); F: Berthellina edwardsi (13 mm); G: Aegires sublaevis (7 mm; the illustrated specimen is from the southern coast of Madeira Island); H: Tambja ceutae (20 mm). (Página derecha) Figura 2. A: Chelidonura africana (10 mm; ejemplar capturado en Porto Santo el 24 Junio 1999); B: Aplysia parvula (20 mm); C: Tylodina perversa (7 mm); D: Umbraculum umbraculum (50 mm de longitud de la concha); E: Elysia flava (9 mm); F: Berthellina edwardsi (13 mm); G: Aegires sublaevis (7 mm; el ejemplar ilustrado proviene de la costa sur de la Isla de Madeira); H: Tambja ceutae (20 mm).

78 MALAQUIAS ET AL .: Opisthobranch molluscs from Porto Santo Island

A B

C D

E F

G H

79 Iberus , 19 (1), 2001

twelve of them are new records for mainly to the Lusitanic + Mauritanic + Porto Santo island. Table I shows this Mediterranean area, being the temperate news records and all the explicit histori - caracter (Mauritanic + Mediterranean) cal and recently references for opistho - represented by the 17.4% of the total. branch molluscs on Porto Santo island. Those opisthobranch species only collected in the central Macaronesian archipelagos (Madeira islands and DISCUSSION Canary islands) are here considered endemic of this area, and reach the 13% Despite the new records for Porto of the total ( Discodoris confusa , Pyruncu - Santo, it must be pointed out that all the lus spretus and Philine desmotis ). species were already known for The presence of widely distributed Madeira Island. Our record of Elysia species (circuntropical, 8.7%; amphia - flava is a confirmation of the hypotheti - tlantic, 4.4%), as well as, temperate or cal occurrence of this species in the subtropical NE Atlantic species is not archipelago since Ortea, Moro and Espi - very significant (8.7%). nosa (1997) have quoted this sacoglos - In conclusion, Porto Santo possesses san species for Madeira without provi - an intermediate position between the ding any information about the location European and African faunae. The of those specimens. However, the geo - South European and North African graphical distribution given by Ortea, species are the most important compo - Moro, Bacallado and Espinosa (1998) for nents, being moderately low the partici - this species does not include Madeira. pation of widely distributed species and Four apparently undescribed species, central Macaronesian endemism. Addi - two of them belonging to the cephalaspi - tional data from future campaigns will dean genus Runcina and the remaining surely improve our knowledge about to the nudibranch genera Geitodoris and the biogeographical relationships of the Cratena , were also collected and are different Macaronesian archipelagos. currently under study. Another interesting aspect is the evalua - Taking in account the present results tion of the importance of these islands (excluding the unidentified species) and as intermediate steps in the dispersion the bibliographical data, we can say that of temperate-subtropical species, as well the known opisthobranch fauna in Porto as, the possible gradient of endemic Santo island comprises a total of 28 species, species from Azores throughout 10 belonging to the Cephalaspidea, 1 to Madeira and Canary up to Cape Verde, the Anaspidea, 2 to the Sacoglossa, 2 to following the Eastern Gulf Stream the Tylodinoidea, 1 to the Pleurobran - branch and Canary current influence. choidea and 12 to the Nudibranchia. Some remarks can be commented taking into consideration the geographic ACKNOWLEDGEMENTS distribution of the species collected in Porto Santo Island. Most of the species Thanks are due to the Clube Naval do (65.2%) are considered NE Atlantic Porto Santo, the Administração de Portos Mediterranean species. About half of da Região Autónoma da Madeira, the these (34 % of the total) are restricted crew of the vessel Fonte da Areia and to

(Right page) Figure 3. A: Plocamopherus maderae (20mm); B: Chromodoris purpurea (7mm); C: Hypselodoris picta (50mm); D: Aldisa smaragdina (12mm); E: Discodoris confusa (40mm); F: Platy - doris argo (28mm); G: Aldisa smaragdina (23mm). (Página derecha) Figura 3. A: Plocamopherus maderae (20mm); B: Chromodoris purpurea (7mm); C: Hypselodoris picta (50mm); D: Aldisa smaragdina (12mm); E: Discodoris confusa (40mm); F: Platydoris argo (28mm); G: Aldisa smaragdina (23mm).

80 MALAQUIAS ET AL .: Opisthobranch molluscs from Porto Santo Island

A B

D E

F G

81 Iberus , 19 (1), 2001

the Directive Staff of the Escola B+S Pro - versidades Portuguesas, acções integra - fessor Dr. Francisco de Freitas Branco das Luso-Espanholas E91/00 and Subdi - (Porto Santo) for all the logistic support rección General de Formación y Promo - and facilities supplied during our stay in ción del Conocimiento, Ministerio de Porto Santo island. Educación y Cultura “HP1999-0093” and This work was partially sponsored by by the Scientific Affairs Division from the CRUP-Conselho de Reitores das Uni - NATO, reference action CRG.970607.

BIBLIOGRAPHY

FONSECA , L. C., G UERREIRO , J. AND GIL , J., ORTEA , J., M ORO , L., AND ESPINOSA , J., 1997. 1995. Note on the macrozoobenthos of the Nuevos datos sobre el género Elysia Risso, upper level sediments of Porto Santo Is - 1818 (Opisthobranchia: Sacoglossa) en el land (Madeira, Portugal). Boletim do Museu Atlántico. Revista de la Academia Canaria de Municipal do Funchal , Suplemento 4: 233- Ciencias , 9 (número 2, 3 y 4): 141-155. 252. ORTEA , J., M ORO , L., B ACALLADO , J. J. AND ES- MIKKELSEN , P. M., 1996. The evolutionary re - PINOSA , J., 1998. Catálogo abreviado de las es - lationships of Cephalaspidea s. l. (Gastro - pecies del orden Sacoglossa (=Ascoglossa, poda: Opisthobranchia): a phylogenetic Mollusca: Opisthobranchia) de las islas Ca - analysis. Malacologia , 37 (2): 375-442. narias y de Cabo Verde. Revista de la Acade - NOBRE , A., 1937. Moluscos Testáceos Marin - mia Canaria de Ciencias , 10 (número 4): 85-96. hos do Arquipélago da Madeira. Memórias e WATSON , R. B., 1897. On the Marine Mollusca Estudos do Museu Zoológico da Universidade from Madeira; with Descriptions of Thirty- de Coimbra , 101p. five new Species, and an Index-List of all the NORDSIECK , F., 1972. Die europäischen Mee - know Sea-dwelling Species of that Island. resschnecken (Opisthobranchia mit Pyramidelli - Linnean Society’s Journal – Zoology , 26: 18-320. dae; Rissoacea) vom Eismeer bis Kap Verden, WIRTZ , P., 1994. Three shrimps, five nudi - Mittelmeer und Schwarzes Meer . Gustav Fischer branchs, and two tunicates new for the ma - Verlag, 327p. rine fauna of Madeira. Boletim do Museu Mu - NORDSIECK , F. AND GARCÍA -T ALAVERA , F., 1979. nicipal do Funchal , 46 (257): 167-172. Moluscos marinos de Canarias y Madera (Gas - WIRTZ , P., 1999. Opisthobranch Molluscs from tropoda) . Aula de Cultura de Tenerife, 208p., the archipelago of Madeira. Vita Marina , 46 pls. I-XLVI. (1-2): 1-18.